Older versions of extensions?

I’m trying to get an old project into a compile-suitable shape for Bring Out Your Dead. The problem is, it was mostly coded back in the days before 6L02, and trying to update it to 6M62 has run afoul of a known abject-failure bug (the one involving topics).

The Inform site stores old versions, which is great! I rolled back to 6G60, but then the problem was that extensions which had been updated for post-6L02 - notably Plurality - obviously don’t play nice with Custom Library Messages. And I can’t seem to find anywhere that older versions of extensions are stored. Anybody got any ideas?

(I tried to split the difference, went with 6L02 in the hope that it hadn’t introduced the topic bug yet, and got a “You wrote :” bug that I can’t diagnose because I have no idea which line of the 60,000-word source is causing it.)

These may help:

github.com/i7/archive/tree/6G60
github.com/i7/extensions/tree/6G60

Plurality was built in though, so you’d just need to extract it from the 6G60 installer.